Tach works then doesnt

[Aernan]

I have the optional Tachometer in my truck. When I start the truck it goes from 0-max then back. It works find for a while then sometimes it goes zero and back on. Today it worked for like 10 min then back to zero to stay there.

My Volts gage also does not work so I know I will be into my dash soon enough.

I read the TM TM 9-2320-365-10 Table 3-2 it says to "notify Unit Maintenance".

Can someone point me in the right direction?

 

[Suprman]

Follow troubleshooting for voltage gage not working. Could be some bad connection or a lousy ground somewhere. Lots of little gremlins to work out of the machine.